Phenylcarbazole-based compounds and fluorene-based compounds and organic light emitting device and flat panel display device comprising the same

ABSTRACT

Provided are an organic light emitting device including: a substrate; a first electrode; a second electrode; and an organic layer interposed between the first electrode and the second electrode and including an emission layer, wherein one of the first electrode and the second electrode is a reflective electrode and the other is a semitransparent or transparent electrode, and wherein the organic layer includes a layer having at least one of the compounds having at least one carbazole group, and a flat panel display device including the organic light emitting device. The organic light emitting device has low driving voltage, excellent current density, high brightness, excellent color purity, high efficiency, and long lifetime.

CROSS-REFERENCE TO RELATED APPLICATIONS

This application makes reference to, incorporates the same herein, andclaims all benefits accruing under 35 U.S.C. §120 as a Continuation ofU.S. Ser. No. 11/806,039 filed on 29 May 2007. Parent application U.S.Ser. No. 11/806,039 is a Continuation-in-Part of U.S. Ser. No.11/286,421, entitled PHENYLCARBAZOLE-BASED COMPOUND AND ORGANICELECTROLUMINESCENT DEVICE EMPLOYING THE SAME, filed on 25 Nov. 2005 toand issued as U.S. Pat. No. 8,021,764 on 20 Sep. 2011, and incorporatedherein by reference in its entirety, U.S. Ser. No. 11/181,706, entitledPHENYLCARBAZOLE COMPOUNDS AND ORGANIC ELECTROLUMINESCENCE DEVICES USINGTHE SAME, filed on 13 Jul. 2005 and issued as U.S. Pat. No. 7,431,997 on7 Oct. 2008, and incorporated herein by reference in its entirety, andU.S. Ser. No. 11/097,182, entitled FLUORENE-BASED COMPOUND AND ORGANICELECTROLUMINESCENT DISPLAY DEVICE USING THE SAME, filed on 4 Åpr. 2005and issued as U.S. Pat. No. 7,737,627 on 15 Jun. 2010, and incorporatedherein by reference in its entirety. All benefits available under 35U.S.C. §120 are claimed from each of the above-referenced parent patentapplications.

This application also claims priority from Korean Patent Application KR10-2006-0048306, entitled ORGANIC LIGHT EMITTING DEVICE AND FLAT PANELDISPLAY DEVICE COMPRISING THE SAME, filed 29 May 2006, and incorporatedherein by reference in its entirety, Korean Patent Application KR10-2004-0098747, entitled PHENYLCARBAZOLE-BASED COMPOUND AND ORGANICELECTROLUMINESCENT DEVICE EMPLOYING THE SAME, filed on 29 Nov. 2004, andincorporated herein by reference in its entirety, Korean PatentApplication KR 10-2004-0054700, entitled PHENYLCARBAZOLE COMPOUNDS ANDORGANIC ELECTROLUMINESCENCE DEVICES USING THE SAME, filed on 14 Jul.2004, and incorporated herein by reference in its entirety, and KoreanPatent Application KR 10-2004-0022877, entitled FLUORENE-BASED COMPOUNDAND ORGANIC ELECTROLUMINESCENT DISPLAY DEVICE USING THE SAME, filed on 2Åpr. 2004, and incorporated herein by reference in its entirety. Allrights of priority and benefits available under 35 U.S.C. §119 areclaimed from each of the above-referenced patent applications.

BACKGROUND OF THE INVENTION

1. Field of the Invention

The present invention relates to an organic light emitting device and aflat panel display device, and more particularly, to an organic lightemitting device including an organic layer containing aphenylcarbazole-based compound.

2. Description of the Related Art

Organic light emitting devices are self-emission displays that emitlight by recombination of electrons and holes in an organic layer madeof a fluorescent or phosphorescent compound when a current is applied tothe organic layer. Organic light emitting devices are lightweight, havesimple constituent elements, an easy fabrication process, superior imagequality, and a wide viewing angle. Furthermore, organic light emittingdevices can realize dynamic images and high color purity. Organic lightemitting devices also have electrical properties such as low powerconsumption and low driving voltage suitable for portable electronicequipment.

Organic light emitting devices generally have an organic layer in theform of a multi-layer structure including an electron injection layer,an emission layer, a hole transport layer, etc. instead of includingonly a single emission layer to improve efficiency and to lower drivingvoltage. For example, Japanese Patent Laid-Open Publication No.2002-252089 discloses an organic light emitting device including a holetransport layer.

However, the driving voltage, current density, brightness, color purity,efficiency and lifetime of a conventional organic light emitting devicedo not meet desired levels. Accordingly, these properties must beimproved.

SUMMARY OF THE INVENTION

The present invention provides an improved organic light emittingdevice.

The present invention provides an organic light emitting deviceincluding an organic layer containing a compound that has excellent holemobility between a pair of electrodes capable of generating resonanceduring the operation of the light emitting device, an organic lightemitting device including a hole injection layer having a predeterminedrange of thickness between a pair of electrodes capable of generatingresonance during the operation of the light emitting device, and a flatpanel display device including the organic light emitting device.

According to an aspect of the present invention, there is provided anorganic light emitting device including: a substrate; a first electrode;a second electrode; and an organic layer interposed between the firstelectrode and the second electrode and including an emission layer,wherein one of the first electrode and the second electrode is areflective electrode and the other is a semitransparent or transparentelectrode, and wherein the organic layer comprises a layer including atleast one of compounds represented by Formulae 1, 2, and 3 below.

Here, X is one of, a substituted or unsubstituted C₁-C₃₀ alkylene group,a substituted or unsubstituted C₂-C₃₀ alkenylene group, a substituted orunsubstituted C₆-C₃₀ arylene group, a substituted or unsubstitutedC₁-C₃₀ heteroarylene group, and a substituted or unsubstituted C₂-C₃₀hetero ring;

Each R₁, each R₂, each R₃, R₄, R₅, R₆, R₇ and R₈ are each independentlyone of a hydrogen atom, a substituted or unsubstituted C₁-C₃₀ alkylgroup, a substituted or unsubstituted C₁-C₃₀ alkoxy group, a substitutedor unsubstituted C₆-C₃₀ aryl group, a substituted or unsubstitutedC₆-C₃₀ aryloxy group, a substituted or unsubstituted C₂-C₃₀ hetero ring,a substituted or unsubstituted C₅-C₃₀ polycyclic condensed ring, ahydroxy group, a cyano group, and a substituted or unsubstituted aminogroup, wherein two or more of R₁, R₂ and R₃ can be optionally bound withone another to form a saturated or unsaturated carbon ring, R₄ and R₅,can be optionally bound with one another to form a saturated orunsaturated carbon ring, and two or more of R₆, R₇ and R₈ can beoptionally bound with one another to form a saturated or unsaturatedcarbon ring;

each Ar₁, Ar₂ and Ar₃ are each independently a substituted orunsubstituted C₆-C₃₀ aryl group or a substituted or unsubstituted C₂-C₃₀heteroaryl group;

each Y is independently one of a substituted or unsubstituted C₁-C₃₀alkyl group, a substituted or unsubstituted C₆-C₃₀ aryl group, and asubstituted or unsubstituted C₂-C₃₀ hetero ring; and

each n is independently an integer from 0 to 5.

According to another aspect of the present invention, there is providedan organic light emitting device including: a substrate; a firstelectrode; a second electrode; and an organic layer interposed betweenthe first electrode and the second electrode and including an emissionlayer having a red emission region and a hole injection layer having aregion formed under the red emission region, wherein one of the firstelectrode and the second electrode is a reflective electrode and theother is a semitransparent or transparent electrode, and wherein thethickness of the region of the hole injection layer formed under the redemission region is in the range of 1,600 to 2,200 Å.

According to another aspect of the present invention, there is providedan organic light emitting device including: a substrate; a firstelectrode; a second electrode; and an organic layer interposed betweenthe first electrode and the second electrode and including an emissionlayer having a green emission region and a hole injection layer having aregion formed under the green emission region, wherein one of the firstelectrode and the second electrode is a reflective electrode and theother is a semitransparent or transparent electrode, and wherein thethickness of the region of the hole injection layer formed under thegreen emission region is in the range of 1,400 to 1,800 Å.

According to another aspect of the present invention, there is providedan organic light emitting device including: a substrate; a firstelectrode; a second electrode; and an organic layer interposed betweenthe first electrode and the second electrode and including an emissionlayer having a blue emission region and a hole injection layer having aregion formed under the blue emission region, wherein one of the firstelectrode and the second electrode is a reflective electrode and theother is a semitransparent or transparent electrode, and wherein thethickness of the region of the hole injection layer formed under theblue emission region is in the range of 1,000 to 1,400 Å.

According to another aspect of the present invention, there is provideda flat panel display device including the organic light emitting device,wherein the first electrode of the organic light emitting device iselectrically connected to a source electrode or a drain electrode of athin film transistor.

The organic light emitting device has low driving voltage, excellentcurrent density, high brightness, excellent color purity, highefficiency, and long lifetime. Particularly, the organic light emittingdevice has excellent lifetime.

BRIEF DESCRIPTION OF THE DRAWINGS

A more complete appreciation of the present invention, and many of theabove and other features and advantages of the present invention, willbe readily apparent as the same becomes better understood by referenceto the following detailed description when considered in conjunctionwith the accompanying drawings in which like reference symbols indicatethe same or similar components, wherein:

FIG. 1 schematically illustrates a structure of an organic lightemitting device according to an embodiment of the present invention;

FIG. 2 schematically illustrates an organic light emitting deviceincluding an emission layer comprised of a red emission region, a greenemission region, and blue emission region according to an embodiment ofthe present invention; and

FIGS. 3 through 7 are graphs illustrating current efficiencies,luminance, and driving voltages of an organic light emitting deviceaccording to an embodiment of the present invention.

DETAILED DESCRIPTION OF THE INVENTION

Hereinafter, the present invention will now be described more fully withreference to the accompanying drawings, in which exemplary embodimentsof the invention are shown. The invention may, however, be embodied inmany different forms and should not be construed as being limited to theembodiments set forth herein; rather, these embodiments are provided sothat this disclosure will be thorough and complete, and will fullyconvey the concept of the invention to those skilled in the art.

An organic light emitting device according to an embodiment of thepresent invention includes a substrate, a first electrode, a secondelectrode and an organic layer. The organic layer is disposed betweenthe first electrode and the second electrode and includes an emissionlayer. The organic layer can emit red, green, and/or blue lightaccording to a material used to form the emission layer.

One of the first electrode and the second electrode is a reflectiveelectrode and the other is a semitransparent or transparent electrode.Accordingly, resonance may occur between the first electrode and thesecond electrode during the operation of the light emitting device.Thus, the light generated in the organic layer between the firstelectrode and the second electrode resonates between the first electrodeand the second electrode during the operation of the light emittingdevice, and the light is extracted from of the organic light emittingdevice. Thus, luminance of the light and light emitting efficiency canbe enhanced.

The first electrode may be formed on the substrate. For example, thefirst electrode may be a reflective electrode, and the second electrodemay be a semitransparent or transparent electrode. Accordingly, thelight generated in the organic layer between the first electrode and thesecond electrode resonates between the first electrode and the secondelectrode during the operation of the light emitting device, and thelight is extracted through the second electrode, that is, in a directionaway from the substrate.

The organic layer of the organic light emitting device according to thecurrent embodiment of the present invention may include a layercontaining a phenylcarbazole-based compound. In particular, the organiclayer may include a layer including at least one of the compoundsrepresented by Formulae 1, 2, and 3 below.

Here, X is one of a substituted or unsubstituted C₁-C₃₀ alkylene group,a substituted or unsubstituted C₂-C₃₀ alkenylene group, a substituted orunsubstituted C₆-C₃₀ arylene group, a substituted or unsubstitutedC₂-C₃₀ heteroarylene group, and a substituted or unsubstituted C₂-C₃₀hetero ring;

Each R₁, each R₂, each R₃, R₄, R₅, R₆, R₇ and R₈ are each independentlyone of a hydrogen atom, a substituted or unsubstituted C₁-C₃₀ alkylgroup, a substituted or unsubstituted C₁-C₃₀ alkoxy group, a substitutedor unsubstituted C₆-C₃₀ aryl group, a substituted or unsubstitutedC₆-C₃₀ aryloxy group, a substituted or unsubstituted C₂-C₃₀ hetero ring,a substituted or unsubstituted C₂-C₃₀ polycyclic condensed ring, ahydroxy group, a cyano group, and a substituted or unsubstituted aminogroup, wherein two or more of R₁, R₂ and R₃ can be optionally bound withone another to form a saturated or unsaturated carbon ring, R₄ and R₅,can be optionally bound with one another to form a saturated orunsaturated carbon ring, and two or more of R₆, R₇ and R₈ can beoptionally bound with one another to form a saturated or unsaturatedcarbon ring;

-   -   each Ar₁, Ar₂ and Ar₃ are each independently a substituted or        unsubstituted C₆-C₃₀ aryl group or a substituted or        unsubstituted heteroaryl group;

each Y is independently one of a substituted or unsubstituted C₁-C₃₀alkyl group, a substituted or unsubstituted C₆-C₃₀ aryl group, and asubstituted or unsubstituted C₂-C₃₀ hetero ring; and

-   -   each n is independently an integer from 0 to 5.

The compounds represented by Formulae 1, 2, and 3 have a stiff carbazolegroup, and thus the glass transition temperature or the melting point ofthe compounds increases. During the operation of the organic lightemitting device according to the current embodiment of the presentinvention, the compounds are highly resistant to heat generated in theorganic layer, between the organic layers, or between the organic layerand the electrode according to Joule's Law, and are stable in a hightemperature environment. Thus, when the compounds are used to form theorganic layer of the organic light emitting device of the presentembodiment, long lifetime and excellent luminance can be obtained.

In particular, the compounds represented by Formulae 1 and 2 which havetwo or more carbazole groups may provide long lifetime and excellentbrightness.

In addition, the organic light emitting device of the present embodimentincluding an organic layer containing a compound represented by Formula1, 2, or 3 has excellent stability during storage and operation. Thisfeature can be explained by, for example, but not limited to, a high Tg(glass transition temperature) of the compound represented by Formula 1,2, or 3.

The compound represented by Formula 1 may include a compound representedby Formula 1a below, but is not limited thereto.

Here, each R₁, each R₂, and each R₃ are each independently one of ahydrogen atom, a substituted or unsubstituted C₁-C₃₀ alkyl group, asubstituted or unsubstituted C₁-C₃₀ alkoxy group, a substituted orunsubstituted C₆-C₃₀ aryl group, a substituted or unsubstituted C₆-C₃₀aryloxy group, a substituted or unsubstituted hetero ring, a substitutedor unsubstituted C₅-C₃₀ polycyclic condensed ring, a hydroxy group, acyano group, and a substituted or unsubstituted amino group, wherein twoor more of R₁, R₂ and R₃ can be optionally bound with one another toform a saturated or unsaturated carbon ring; and

each Q₁ is independently one of a hydrogen atom, a cyano group, afluorine atom, a substituted or unsubstituted C₁-C₃₀ alkyl group, asubstituted or unsubstituted C₆-C₃₀ aryl group, a substituted orunsubstituted C₂-C₃₀ hetero ring, and a substituted or unsubstitutedamino group.

The compound represented by Formula 1 may include a compound representedby Formula 1b below, but is not limited thereto.

Here, each R₁, each R₂, and each R₃ are each independently one of ahydrogen atom, a substituted or unsubstituted C₁-C₃₀ alkyl group, asubstituted or unsubstituted C₁-C₃₀ alkoxy group, a substituted orunsubstituted C₆-C₃₀ aryl group, a substituted or unsubstituted C₆-C₃₀aryloxy group, a substituted or unsubstituted C₂-C₃₀ hetero ring, asubstituted or unsubstituted C₅-C₃₀ polycyclic condensed ring, a hydroxygroup, a cyano group, and a substituted or unsubstituted amino group,wherein two or more of R₁, R₂ and R₃ can be optionally bound with oneanother to form a saturated or unsaturated carbon ring; and

each Q₂ is one selected from the group consisting of a hydrogen atom, acyano group, a fluorine atom, a substituted or unsubstituted C₁-C₃₀alkyl group, a substituted or unsubstituted C₆-C₃₀ aryl group, asubstituted or unsubstituted C₂-C₃₀ hetero ring, and a substituted orunsubstituted amino group.

The compound represented by Formula 2 may include a compound representedby Formula 2a below, but is not limited thereto.

Here, R₄ and R₅ are each independently one of a hydrogen atom, asubstituted or unsubstituted C₁-C₃₀ alkyl group, a substituted orunsubstituted C₁-C₃₀ alkoxy group, a substituted or unsubstituted C₆-C₃₀aryl group, a substituted or unsubstituted C₆-C₃₀ aryloxy group, asubstituted or unsubstituted C₂-C₃₀ hetero ring, a substituted orunsubstituted C₅-C₃₀ polycyclic condensed ring, a hydroxy group, a cyanogroup, and a substituted or unsubstituted amino group, wherein R₄, andR₅ can be optionally bound with one another to form a saturated orunsaturated, carbon ring; and

Q₃ is one of a hydrogen atom, a cyano group, a fluorine atom, asubstituted or unsubstituted C₁-C₃₀ alkyl group, a substituted orunsubstituted C₆-C₃₀ aryl group, a substituted or unsubstituted heteroring, and a substituted or unsubstituted amino group.

The compound represented by Formula 3 may include a compound representedby Formula 3a below, but is not limited thereto.

Here, R₆, R₇ and R₈ are each independently one of a hydrogen atom, asubstituted or unsubstituted C₁-C₃₀ alkyl group, a substituted orunsubstituted C₁-C₃₀ alkoxy group, a substituted or unsubstituted C₆-C₃₀aryl group, a substituted or unsubstituted C₆-C₃₀ aryloxy group, asubstituted or unsubstituted C₂-C₃₀ hetero ring, a substituted orunsubstituted C₅-C₃₀ polycyclic condensed ring, a hydroxy group, a cyanogroup, and a substituted or unsubstituted amino group, wherein two ormore of R₆, R₇ and R₈ can be optionally bound with one another to form asaturated or unsaturated carbon ring; and

Q₄ is one of a hydrogen atom, a cyano group, a fluorine atom, asubstituted or unsubstituted C₁-C₃₀ alkyl group, a substituted orunsubstituted C₆-C₃₀ aryl group, a substituted or unsubstituted C₂-C₃₀hetero ring, and a substituted or unsubstituted amino group.

Hereinafter, examples of the groups used to form the compoundsrepresented by the above formulae will now be described in more detail.

Examples of the unsubstituted C₁-C₃₀ alkyl group may include a methylgroup, an ethyl group, a propyl group, an isobutyl group, a sec-butylgroup, a pentyl group, an iso-amyl group, and a hexyl group. At leastone hydrogen atom in the unsubstituted C₁-C₃₀ alkyl group may besubstituted with a halogen atom, a C₁-C₃₀ alkyl group, a C₁-C₃₀ alkoxygroup, a low alkylamino group, a hydroxy group, a nitro group, a cyanogroup, an amino group, an amidino group, a hydrazine group, a hydrazonegroup, a carboxyl group, a sulfonic acid group, and a phosphoric acidgroup.

Examples of the unsubstituted C₁-C₃₀ alkoxy group may include a methoxygroup, an ethoxy group, a propoxy group, an isobutyloxy group, asec-butyloxy group, a pentyloxy group, an iso-amyloxy group, and ahexyloxy group. At least one hydrogen atom in the unsubstituted C₁-C₃₀alkoxy group may be substituted with the groups described above withreference to the C₁-C₃₀ alkyl group.

The C₆-C₃₀ aryl group indicates a carbocyclic aromatic system containingone or more rings, wherein such rings may be bonded together in apendent manner or may be fused. The term “aryl group” may include anaromatic system such as a phenyl group, a naphthyl group, and atetrahydronaphthyl group. At least one hydrogen atom in the C₅-C₃₀ arylgroup may be substituted with the groups described above with referenceto the C₁-C₃₀ alkyl group.

The C₂-C₃₀ heteroaryl group indicates a monovalent monocyclic ringcompound having 2 to 30 membered rings including C and 1 to 3 heteroatoms selected from the group consisting of N, O, P, and S, wherein suchrings may be bonded together in a pendent manner or may be fused.Examples of the C₂-C₃₀ heteroaryl group may include a pyridyl group, athienyl group, and a furyl group. At least one hydrogen atom in theC₂-C₃₀ heteroaryl group may be substituted with the groups describedabove with reference to the C₁-C₃₀ alkyl group.

Each Ar₁, Ar₂ and Ar₃ are each independently a phenyl group, a C₁-C₁₀alkylphenyl group, a C₁-C₁₀ alkoxyphenyl group, a halophenyl group, acyanophenyl group, a dicyanophenyl group, a trifluoromethoxyphenylgroup, an o-, m-, or p-tolyl group, an o-, m- or p-cumenyl group, amesityl group, a phenoxyphenyl group, a (α,α-dimethylbenzene)phenylgroup, a (N,N′-dimethyl)aminophenyl group, a (N,N′-diphenyl)aminophenylgroup, a (C₁-C₁₀ alkylcyclohexyl)phenyl group, an (anthracenyl)phenylgroup, a biphenyl group, a C₁-C₁₀ alkylbiphenyl group, a C₁-C₁₀alkoxybiphenyl group, a pentalenyl group, an indenyl group, a naphthylgroup, a C₁-C₁₀ alkylnaphthyl group, a C₁-C₁₀ alkoxynaphthyl group, ahalonaphthyl group, a cyanonaphthyl group, a biphenylenyl group, aC₁-C₁₀ alkyl biphenylenyl group, a C₁-C₁₀ alkoxy biphenylenyl group, ananthracenyl group, an azulenyl group, a heptalenyl group, anacenaphthylenyl group, a phenalenyl group, a fluorenyl group, ananthraquinolyl group, a methylanthryl group, a phenanthrenyl group, atriphenylenyl group, a pyrenyl group, a chrysenyl group, anethyl-chrysenyl group, a picenyl group, a perylenyl group, achloroperylenyl group, a pentaphenyl group, a pentacenyl group, atetraphenylenyl group, a hexaphenyl group, a hexacenyl group, arubicenyl group, a coronenyl group, trinaphthylenyl group, a heptaphenylgroup, a heptacenyl group, a pyranthrenyl group, an ovalenyl group, acarbazolyl group, a C₁-C₁₀ alkyl carbazolyl group, a thiophenyl group,an indolyl group, a purinyl group, a benzimidazolyl group, a quinolinylgroup, a benzothiophenyl group, a parathiazinyl group, a pyrrolyl group,a pyrazolyl group, an imidazolyl group, an imidazolinyl group, anoxazolyl group, a thiazolyl group, a triazolyl group, a tetrazolylgroup, an oxadiazolyl group, a pyridinyl group, a pyridazinyl group, apyrimidinyl group, a pyrazinyl group, and a thianthrenyl group, but arenot limited thereto.

More particularly, the compounds represented by Formulae 1, 2, and 3 areeach independently one of Compounds 1 to 62 below, but are not limitedthereto.

The compound represented by Formula 1 may be synthesized through areaction between a phenylcarbazole (B′) with a diamine (C′) according toReaction Scheme 1 below.

Here, X, R₁, R₂, R₃, and Ar₁ are already described above, and Z can behalogen, particularly iodine (I). The reaction can be performed in thepresence of Pd₂(dba)₃ (dba=dibenzylideneacetone), sodium tert-butoxideand tri(tert-butyl)phosphine and at a reaction temperatures in the rangeof 50 to 150.

The layer which is included in the organic layer and which includes atleast one of the compounds represented by Formulae 1, 2, and 3 may be ahole injection layer, a hole transport layer, or a single layer havinghole injecting and transporting properties.

For example, the layer included in the organic layer and including atleast one of the compounds represented by Formulae 1, 2, and 3 may be ahole injection layer.

The thickness of the hole injection layer formed under the red emissionlayer may be in the range of 1,600 to 2,200 Å, and preferably 1,900 to2,200 Å. When the thickness of the hole injection layer formed under thered emission region is within the ranges described above, hole injectingand transporting properties suitable for causing resonance in a redemission layer of the organic layer can be obtained, and thus colorpurity, efficiency of the device, and a driving voltage of the devicemay be improved. In certain embodiments, the thickness of the holeinjection layer formed under the red emission layer may be 1600, 1620,1640, 1660, 1680, 1700, 1720, 1740, 1760, 1780, 1800, 1820, 1840, 1860,1880, 1900, 1920, 1940, 1960, 1980, 2000, 2020, 2040, 2060, 2080, 2100,2120, 2140, 2160, 2180, or 2200 Å. In some embodiments, the thickness ofthe hole injection layer formed under the red emission layer may bewithin a range defined by two of the foregoing thicknesses.

The thickness of the hole injection layer formed under the greenemission region may be in the range of 1,400 to 1,800 Å, and preferably1,600 to 1,800 Å. When the thickness of the hole injection layer iswithin the ranges described above, hole injecting and transportingproperties suitable for causing resonance in a green emission layer ofthe organic layer can be obtained, and thus color purity, efficiency ofthe device, and the driving voltage of the device may be improved. Incertain embodiments, the thickness of the hole injection layer formedunder the green emission layer may be, 1400, 1420, 1440, 1460, 1480,1500, 1520, 1540, 1560, 1580, 1600, 1620, 1640, 1660, 1680, 1700, 1720,1740, 1760, 1780, or 1800 Å. In some embodiments, the thickness of thehole injection layer formed under the green emission layer may be withina range defined by two of the foregoing thicknesses.

The thickness of the hole injection layer formed under the blue emissionregion may be in the range of 1,000 to 1,400 Å, and preferably 1,100 to1,300 Å. When the thickness of the hole injection layer formed under theblue emission region is within the ranges described above, holeinjecting and transporting properties suitable for causing resonance ina blue emission layer of the organic layer can be obtained, and thuscolor purity, efficiency of the device, and the driving voltage of thedevice may be improved. In certain embodiments, the thickness of thehole injection layer formed under the blue emission layer may be, 1000,1020, 1040, 1060, 1080, 1100, 1120, 1140, 1160, 1180, 1200, 1220, 1240,1260, 1280, 1300, 1320, 1340, 1360, 1380, or 1400 Å. In someembodiments, the thickness of the hole injection layer formed under theblue emission layer may be within a range defined by two of theforegoing thicknesses.

The organic layer may further include a hole transport layer.

The total thickness of a region of the hole injection layer formed undera red emission region and the hole transport layer may be in the rangeof 2,000 to 2,400 Å, and preferably 2,100 to 2,300 Å. The thickness ofthe region of the hole injection layer formed under a red emissionregion may be in the range of 1,600 to 2,200 Å, and preferably 1,900 to2,200 Å. When the total thickness of the region of the hole injectionlayer formed under the red emission region and the hole transport layerand/or the thickness of the region of the hole injection layer formedunder the red emission region are within the ranges described above,hole injecting and transporting properties suitable for causingresonance in the red emission layer can be obtained, and thus colorpurity, efficiency of the device, and the driving voltage of the devicemay be improved. In certain embodiments, total thickness of a region ofthe hole injection layer formed under the red emission region and thehole transport layer may be, 2000, 2020, 2040, 2060, 2080, 2100, 2120,2140, 2160, 2180, 2200, 2220, 2240, 2260, 2280, 2300, 2320, 2340, 2360,2380, or 2400 Å. In some embodiments, the total thickness of the holeinjection layer and the hole transport layer formed under the redemission layer may be within a range defined by two of the foregoingthicknesses.

The total thickness of a region of the hole injection layer formed undera green emission region and the hole transport layer may be in the rangeof 1,600 to 2,000 Å, and preferably 1,700 to 1,900 Å. The thickness ofthe region of the hole injection layer formed under the green emissionregion may be in the range of 1,400 to 1,800 Å, and preferably 1,600 to1,800 Å. When the total thickness of the region of the hole injectionlayer formed under the green emission region and the hole transportlayer and/or the thickness of the region of the hole injection layerformed under the green emission region are within the ranges describedabove, hole injecting and transporting properties suitable for causingresonance in the green emission layer can be obtained, and thus colorpurity, efficiency of the device, and a driving voltage of the devicemay be improved. In certain embodiments, total thickness of a region ofthe hole injection layer formed under the green emission region and thehole transport layer may be, 1600, 1620, 1640, 1660, 1680, 1700, 1720,1740, 1760, 1780, 1800, 1820, 1840, 1860, 1880, 1900, 1920, 1940, 1960,1980, or 2000 Å. In some embodiments, the total thickness of the holeinjection layer and the hole transport layer formed under the greenemission layer may be within a range defined by two of the foregoingthicknesses.

The total thickness of a region of the hole injection layer formed undera blur emission region and the hole transport layer may be in the rangeof 1,200 to 1,600 Å, and preferably 1,300 to 1,500 Å. The thickness ofthe region of the hole injection layer formed under the blur emissionregion may be in the range of 1,000 to 1,400 Å, and preferably 1,100 to1,300 Å. When the total thickness of the region of the hole injectionlayer formed under the blur emission region and the hole transport layerand/or the thickness of the region of the hole injection layer formedunder the blur emission region are within the ranges described above,hole injecting and transporting properties suitable for causingresonance in the blue emission layer can be obtained, and thus colorpurity, efficiency of the device, and the driving voltage of the devicemay be improved. In certain embodiments, total thickness of a region ofthe hole injection layer formed under the blue emission region and thehole transport layer may be, 1200, 1220, 1240, 1260, 1280, 1300, 1320,1340, 1360, 1380, 1400, 1420, 1440, 1460, 1480, 1500, 1520, 1540, 1560,1580, or 1600 Å. In some embodiments, the total thickness of the holeinjection layer and the hole transport layer formed under the blueemission layer may be within a range defined by two of the foregoingthicknesses.

An organic light emitting device according to an embodiment of thepresent invention includes: a substrate; a first electrode; a secondelectrode; and an organic layer interposed between the first electrodeand the second electrode and comprising an emission layer having a redemission region and a hole injection layer having a region formed underthe red emission region, wherein one of the first electrode and thesecond electrode is a reflective electrode and the other is asemitransparent or transparent electrode, and wherein the thickness ofthe region of the hole injection layer formed under the red emissionregion is in the range of 1,600 to 2,200 Å, and preferably 1,900 to2,200 Å.

When the thickness of the region of the hole injection layer formedunder the red emission region is within the ranges described above, holeinjecting and transporting properties suitable for causing resonance ina red emission layer can be obtained, and thus color purity, efficiencyof the device, and the driving voltage of the device may be improved.

An organic light emitting device according to an embodiment of thepresent invention includes: a substrate; a first electrode; a secondelectrode; and an organic layer interposed between the first electrodeand the second electrode and comprising an emission layer having a greenemission region and a hole injection layer having a region formed underthe green emission region, wherein one of the first electrode and thesecond electrode is a reflective electrode and the other is asemitransparent or transparent electrode, and wherein the thickness ofthe region of the hole injection layer formed under the green emissionregion in the range of 1,400 to 1,800 Å, and preferably 1,600 to 1,800Å.

When the thickness of the region of the hole injection layer formedunder the green emission region is within the ranges described above,hole injecting and transporting properties suitable for causingresonance in the green emission layer can be obtained, and thus colorpurity, efficiency of the device, the driving voltage of the device maybe improved.

An organic light emitting device according to an embodiment of thepresent invention includes: a substrate; a first electrode; a secondelectrode; and an organic layer interposed between the first electrodeand the second electrode and comprising an emission layer having a blueemission region and a hole injection layer having a region formed underthe blue emission region, wherein one of the first electrode and thesecond electrode is a reflective electrode and the other is asemitransparent or transparent electrode, and wherein the thickness ofthe region of the hole injection layer formed under the blue emissionregion is in the range of 1,000 to 1,400 Å, and preferably 1,100 to1,300 Å.

When the thickness of the region of the hole injection layer formedunder the blue emission region is within the ranges described above,hole injecting and transporting properties suitable for causingresonance in the blue emission layer can be obtained, and thus colorpurity, efficiency of the device, and the driving voltage of the devicemay be improved.

Resonance can occur between the first electrode and the second electrodeof an organic light emitting device according to an embodiment of thepresent invention during the operation thereof. The hole injection layerof the organic layer disposed between the first electrode and the secondelectrode may have a specific thickness according to the color of thelight emitted by the organic layer described above to obtain excellentproperties such as driving voltage, current density, luminance, colorpurity, efficiency and lifetime of the organic light emitting device.

In an organic light emitting device according to an embodiment of thepresent invention, the first electrode can be formed on the substrate.The first electrode may be a reflective electrode and the secondelectrode may be a semitransparent or transparent electrode. Thus,resonance may occur between the first electrode and the second electrodeduring the operation of the device. Accordingly, the light generated inthe organic layer between the first electrode and the second electroderesonates between the first electrode and the second electrode duringthe operation of the organic light emitting device, and the light isextracted through the second electrode, that is, in a direction awayfrom the substrate.

The organic layer of the organic light emitting device may include anemission layer and/or a hole injection layer. The organic layer mayfurther include at least one of a hole transport layer, an electronblocking layer, a hole blocking layer, an electron transport layer, andan electron injection layer. Thus, for example, an organic lightemitting device according to an embodiment of the present invention mayhave a structure of substrate/first electrode/hole injection layer(HIL)/hole transport layer (HTL)/emission layer (EML)/hole blockinglayer (HBL)/electron transport layer (ETL)/electron injection layer(EIL)/second electrode as illustrated in FIG. 1.

Hereinafter, Examples and methods of manufacturing an organic lightemitting device according to an embodiment of the present invention willbe described with reference to the organic light emitting deviceillustrated in FIGS. 1 and 2. FIG. 1 schematically illustrates astructure of an organic light emitting device according to an embodimentof the present invention. FIG. 2 schematically illustrates an organiclight emitting device including red, green, and blue emission layersaccording to an embodiment of the present invention.

Referring to FIG. 2, a first electrode 210 is formed on a substrate 200.Here, the substrate 200, which can be any substrate that is commonlyused in conventional organic light emitting devices, may be a glasssubstrate or a plastic substrate with excellent transparency, surfacesmoothness, ease of treatment, and that is waterproof.

The first electrode 210 may be a reflective electrode, a semitransparentelectrode or a transparent electrode formed of a metal with excellentconductivity such as Li, Mg, Al, Al—Li, Ca, Mg—In, Mg—Ag, and Ca—Al, ora metal oxide with excellent conductivity such as ITO, IZO, and IN₂O₃. Acombination of two or more of the metals or the metal oxides describedabove can also be used.

Then a pixel defining layer 214 which defines regions in which red,green, and blue emission layers will be formed is formed onpredetermined regions. The pixel defining layer 214 can be formed bydeposition or coating, etc. using inorganic materials such as a siliconoxide and a nitride or organic materials having insulating properties.

Then, a HIL 216 and a HTL 218 are sequentially formed on the firstelectrode 210 by thermal evaporation or spin coating according toregions which are defined by the pixel defining layer 214.

The HIL 216 may include at least one of the compounds represented byFormulae 1, 2, and 3. The HTL 218 may include1,3,5-tricarbazolylbenzene, 4,4′-biscarbazolylbiphenyl,polyvinylcarbazole, m-biscarbazolylphenyl,4,4′-biscarbazolyl-2,2′-dimethylbiphenyl,4,4′,4″-tri(N-carbazolyl)triphenylamine,1,3,5-tri(2-carbazolylphenyl)benzene,1,3,5-tris(2-carbazolyl-5-methoxyphenyl)benzene,bis(4-carbazolylphenyl)silane,N,N′-bis(3-methylphenyl)-N,N′-diphenyl-[1,1-biphenyl]-4,4′-diamine(TPD), N,N′-di(naphthalene-1-yl)-N,N′-diphenylbenzidine (α-NPD),N,N′-diphenyl-N,N′-bis(1-naphthyl)-(1,1′-biphenyl)-4,4′-diamine (NPB),IDE 320 (Idemitsu Corporation),poly(9,9-dioctylfluorene-co-N-(4-butylphenyl)diphenylamine (TFB), orpoly(9,9-dioctylfluorene-co-bis-(4-butylphenyl-bis-N,N-phenyl-1,4-phenylenediamin(PFB), but is not limited to the above-described examples.

The thickness of the HIL 216 and the HTL 218 are described above.

The HIL 216 can be formed using a known method such as vacuumdeposition, spin coating, casting, Langmuir Blodgett (LB), or the like.

When the HIL 216 is formed by vacuum deposition, vacuum depositionconditions may vary according to a compound that is used to form the HIL216, and the structure and thermal properties of the HIL 216 to beformed. In general, however, conditions for vacuum deposition mayinclude a deposition temperature of 100-500° C., a pressure of 10⁻⁸-10⁻³torr, and a deposition speed of 0.01-100 Å/sec.

When the HIL 216 is formed by spin coating, coating conditions may varyaccording to a compound that is used to form the HIL 216, and thestructure and thermal properties of the HIL 216 to be formed. Ingeneral, however, the coating speed may be in the range of about 2000 to5000 rpm, and a temperature for heat treatment, which is performed toremove a solvent after coating may be in the range of about 80 to 200°C.

The HTL 218 can be formed using a known method such as vacuumdeposition, spin coating, casting, LB, or the like.

When the HTL 218 is formed by vacuum deposition and spin coating,conditions for deposition and coating are similar to those for formationof the HIL 216, although conditions for deposition and coating may varyaccording to a material that is used to form the HTL 218.

Red, green and blue EMLs, 220, 225, and 230 are formed on the HTL 218.The material used to form the red, green and blue EMLs, 220, 225, and230 is not limited.

For example, DCM1, DCM2, Eu(thenoyltrifluoroacetone)3 (Eu(TTA)₃), andbutyl-6-(1,1,7,7,-tetramethyljulolidyl-9-enyl)-4H-pyran (DCJTB) can beused to form the red EML 220. Alternatively, a dopant such DCJTB can bedeposited with Alq3, Alq3 and rubrene can be co-deposited and a dopantcan be deposited thereon, or dopants such as BTPIr or RD 61 can bedeposited with 4,4′-N—N′-dicarbazole-biphenyl (CBP) to form the red EML220, but the present invention is not limited to the above-describedexamples.

For example, Coumarin 6, C545T, quinacridone, and Ir(ppy)₃ can be usedto form the green EML 225. Alternatively, a dopant such Ir(ppy)₃ can bedeposited with CBP, or a dopant such as a coumarin-based material can bedeposited with Alq3 as a host to form the green EML 225, but the presentinvention is not limited to the above-described examples. Examples ofthe coumarin-based dopant may include C314S, C343S, C7, C7S, C6, C6S,C314T, and C545T.

For example, oxadiazole dimer dyes (Bis-DAPDXP), Spiro compounds(Spiro-DPVBi, Spiro-GP), triarylamine compounds, bis(styryl) amine(DPVBi, DSA), CzTT, Anthracene, TPB, PPCP, DST, TPA, OXD-4, BBOT,AZM-Zn, and BH-013× (Idemitsu Corporation) which is an aromatichydrocarbon compound containing a naphthalene moiety can be used to formthe blue EML 230. Alternatively, a dopant such IDE 105 (IdemitsuCorporation) can be deposited on IDE 140 (Idemitsu Corporation) to formthe blue EML 230, but the present invention is not limited to theabove-described examples.

The thickness of the red, green and blue EMLs, 220, 225 and 230 may bein the range of 200 to 500 Å, and preferably 300 to 400 Å. The thicknessof each of the red, green and blue, EMLs, 220, 225 and 230 may be thesame or different. When the thickness of the red, green and blue, EMLs,220, 225 and 230 is within the ranges described above, excellentlifetime and driving voltage of the light emitting device may beobtained.

The red, green and blue, EMLs, 220, 225 and 230 can be formed using aknown method such as vacuum deposition, spin coating, casting, LB, orthe like. When the red, green and blue, EMLs, 220, 225 and 230 areformed by vacuum deposition and spin coating, conditions for depositionand coating are similar to those for formation of the HIL 216, althoughconditions for deposition and coating may vary according to the materialthat is used to form the red, green and blue, EMLs, 220, 225 and 230.

A HBL (not shown) can optionally be formed on the red, green and blue,EMLs, 220, 225 and 230 by vacuum deposition or spin coating. A materialthat is used to form the HBL should have a capability of transportingelectrons and an ionization potential higher than the red, green andblue, EMLs, 220, 225 and 230, and thus examples of the material mayinclude bis(2-methyl-8-quinolato)-(p-phenylphenolato)-aluminum (Balq),bathocuproine (BCP), and tris(N-aryl benzimidazole) (TPBI), but are notlimited thereto.

The thickness of the HBL may be in the range of 30 to 60 Å, andpreferably 40 to 50 Å. When the thickness of the HBL is within theranges described above, a proper hole blocking capability and thedriving voltage of the device may be obtained.

The HBL can be formed using a known method such as vacuum deposition,spin coating, casting, LB, or the like. When the HBL is formed by vacuumdeposition and spin coating, conditions for deposition and coating aresimilar to those for formation of the HIL 216, although conditions fordeposition and coating may vary according to the material that is usedto form the HBL.

An ETL 240 can be optionally formed by vacuum deposition or spin coatingon the red, green and blue, EMLs, 220, 225 and 230, or the HBL. Thematerial that is used to form the ETL 240 may be Alq3, but is notlimited thereto.

The thickness of the ETL 240 may be in the range of about 100 to 400 Å,and preferably, 250 to 350 Å. When the thickness of the ETL 240 isgreater than 100 Å, proper charge balance can be maintained. On theother hand, when the thickness of the ETL 240 is less than 400 Å, properdriving voltage of the device may be obtained.

The ETL 240 can be formed using a known method such as vacuumdeposition, spin coating, casting, LB, or the like. When the ETL 240 isformed by vacuum deposition and spin coating, conditions for depositionand coating are similar to those for formation of the HIL 216, althoughconditions for deposition and coating may vary according to the materialthat is used to form the ETL 240.

An EIL 250 may be formed by vacuum deposition or spin coating on the ETL240. The material that is used to form the EIL 250 may be BaF₂, LiF,NaCl, CsF, Li₂O, BaO, Liq, or the like, but is not limited thereto.

The thickness of the EIL 250 may be in the range of 2 to 100 Å,preferably, 2 to 5 Å, and more preferably 2 to 4 Å. When the thicknessof the EIL 250 is within the ranges described above, proper electroninjecting capability and the driving voltage of the device may beobtained.

The EIL 250 can be formed using a known method such as vacuumdeposition, spin coating, casting, LB, or the like. When the EIL 250 isformed by vacuum deposition and spin coating, conditions for depositionand coating are similar to those for formation of the HIL 216, althoughconditions for deposition and coating may vary according to the materialthat is used to form the EIL 250.

A second electrode 260 is formed on the EIL 250 by deposition to therebycomplete the manufacture of the organic light-emitting device accordingto the current embodiment of the present invention.

The material that is used to form the second electrode 260 can be atransparent metal oxide with excellent conductivity such as ITO, IZO,SnO₂, and ZnO, Li, Mg, Al, Al—Li, Ca, Mg—In, Mg—Ag, Ca—Al can be used toform a thin film of the second electrode 260, and thus the secondelectrode 260 can be a reflective electrode, a semitransparentelectrode, or a transparent electrode in a various manner. The materialused to form the second electrode 260 is not limited to theabove-described examples.

The first electrode 210 and the second electrode 260 can be an anode ora cathode.

The organic light emitting device according to the current embodiment ofthe present invention can be utilized in various types of flat paneldisplay devices such as a passive matrix organic light emitting deviceand an active matrix organic light emitting device. When the organiclight emitting device of the present embodiment is utilized in an activematrix organic light emitting device, the first electrode 210 as a pixelelectrode that is formed on the substrate 200 can be electricallyconnected to a source electrode or a drain electrode of a thin filmtransistor. The organic light emitting device of the present embodimentcan also be utilized in a flat panel display that can realize images intwo sides.

Hereinafter, the present invention will be described more specificallywith reference to the following Synthesis Examples of Compounds 8, 9,10, 11, 14, 28, 35, and 56 and Examples of an organic light emittingdevice according to an embodiment of the present invention will now bedescribed in detail. However, the Synthesis Examples and the Examplesare not intended to limit the scope of the present invention.

EXAMPLES Synthesis Example 1 Synthesis of Compound 8

Compound 8 was synthesized through Reaction Scheme 2 below.

Synthesis of Intermediate A

16.7 g (100 mmol) of carbazole, 26.5 g (130 mmol) of iodobenzene, 1.9 g(10 mmol) of CuI, 138 g (1 mol) of K₂CO₃, and 530 mg (2 mmol) of18-crown-6 were dissolved in 500 ml of1,3-Dimethyl-3,4,5,6-tetrahydro-(1H)-pyrimidinone (DMPU), and heated at170° C. for 8 hours.

After the reaction terminated, the reaction mixture was cooled to roomtemperature, and the resultant solid substance was filtered. Then asmall amount of ammonium hydroxide was added to the filtered solution.The resultant was washed three times with 300 ml of diethylether, anddried in MgSO₄ under reduced pressure. As a result, a crude product wasobtained. The crude product was purified using a silica gel columnchromatography to produce 22 g of Intermediate A as a white solid (yield90%).

¹H NMR (CDCl₃, 400 MHz) δ (ppm) 8.12 (d, 2H), 7.58-7.53 (m, 4H),7.46-7.42 (m, 1H), 7.38 (d, 4H), 7.30-7.26 (m, 2H); ¹³C NMR (CDCl₃, 100MHz) δ (ppm) 141.0, 137.9, 130.0, 127.5, 127.3, 126.0, 123.5, 120.4,120.0, 109.9.

Synthesis of Intermediate B

2.433 g (10 mmol) of Intermediate A was added to 100 ml of 80% aceticacid. 1.357 g (5.35 mmol) of iodine (I₂) and 0.333 g (1.46 mmol) ofo-periodic acid (H₅IO₆) were added thereto in the solid state. Then, themixture was stirred at 80° C. in a nitrogen atmosphere for 2 hours.

After the reaction terminated, the resultant solution was extractedthree times with 50 ml of ethylether. An organic layer collected fromthe mixture was dried over MgSO₄ to evaporate the solvent. As a result,the dried result was purified using a silica gel column chromatographyto produce 3.23 g of Intermediate B as a white solid (yield 87%).

¹H NMR (CDCl₃, 300 MHz) δ (ppm) 8.43 (d, 1H), 8.05 (d, 1H), 7.62 (dd,1H), 7.61-7.75 (m, 2H), 7.51-7.43 (m, 3H), 7.41-7.35 (m, 2H), 7.27 (dd,1H), 7.14 (d, 1H)

Synthesis of Intermediate C

3.12 g (10 mmol) of 4,4′-dibromodiphenyl, 2.3 ml (25 mmol) of aniline,2.9 g (30 mmol) of t-BuONa, 183 mg (0.2 mmol) of Pd₂(dba)₃, 20 mg (0.1mmol) of P(t-Bu)₃ were dissolved in 30 ml of toluene and the mixture wasstirred at 90° C. for 3 hours.

The reaction mixture was cooled to room temperature, and the resultantsolution was extracted three times with 30 ml of distilled water anddiethylether. A precipitate in an organic layer was filtered, washedwith acetone and diethylether, and dried in a vacuum condition toproduce 0.3 g of Intermediate C (yield 90%).

Intermediate C was identified by ¹H-NMR.

¹H NMR (DMSO-d₆, 400 MHz) δ (ppm) 8.22 (s, 2H), 7.48 (d, 4H), 7.23 (t,4H), 7.10 (dd, 8H), 6.82 (t, 2H); ¹³C NMR (DMSO-d₆, 100 MHz) δ (ppm)145.7, 144.3, 133.7, 131.4, 128.7, 121.2, 119.2, 118.9.

Synthesis of Compound 8

912 mg (2.47 mmol) of Intermediate B, 336.4 mg (1 mmol) of IntermediateC, 300 mg (3 mmol) of t-BuONa, 40 mg (0.02 mmol) of Pd₂(dba)₃, 3 mg(0.01 mmol) of P(t-Bu)₃ were dissolved in 5 ml of toluene and themixture was stirred at 90° C. for 3 hours.

After the reaction terminated, the resultant mixture was cooled to roomtemperature, and the resultant solution was extracted three times withdistilled water and 30 ml of ethylether. An organic layer collected fromthe mixture was dried over MgSO₄ to evaporate the solvent. As a result,the dried result was purified using a silica gel column chromatographyto produce 570 mg of Compound 8 as a yellow solid (Yield 70%).

¹H NMR (CDCl₃, 300 MHz) δ (ppm) 7.99 (d, 2H), 7.95 (s, 2H), 7.61-7.57(m, 8H), 7.48-7.32 (m, 12H), 7.27-7.19 (m, 8H), 7.18-7.10 (m, 8H), 6.96(t, 2H); ¹³C NMR (CDCl₃, 100 MHz) δ (ppm) 148.4, 147.3, 141.3, 140.4,138.0, 137.6, 133.9, 129.9, 129.1, 127.4, 127.1, 127.0, 126.1, 125.6,124.3, 123.0, 122.9, 122.8, 121.7, 120.5, 119.9, 118.5, 110.7, 109.9.

Compound 8 was diluted in CHCl₃ to a concentration of 0.2 mM and a UVSpectrum of the diluted Compound 8 was obtained. Maximum absorptionwavelengths were 353, 306 and 238 nm.

Td (decomposition temperature) and Tg (glass transition temperature) ofCompound 8 were measured by performing thermal analysis using thermogravimetric analysis (TGA) and differential scanning calorimetry (DSC)under the following conditions: N₂ atmosphere, temperatures of roomtemperature to 600° C. (10° C./min)-TGA and of room temperature to 400°C.-DSC, and Pan Type: Pt Pan in disposable Al Pan (TGA) and disposableAl pan (DSC). The measured Td was 494° C. and Tg was 153° C.

A highest occupied molecular orbital (HOMO) level of 5.16 eV and alowest occupied molecular orbital (LUMO) level of 2.16 eV were obtainedusing AC-2 that measures UV absorption spectrum and ionizationpotential.

Synthesis Example 2 Synthesis Compound 9

Compound 9 was synthesized through Reaction Scheme 3 below.

Intermediate D was synthesized with a yield of 85% in the same manner asin Synthesis Example 1, except that p-tolylamine was used instead ofaniline in the synthesis of Intermediate C of Synthesis Example 1. Then,2 g (Yield 80%) of Compound 9 as a yellow solid was produced in the samemanner as in Synthesis Example 1, except that Intermediate D was usedinstead of Intermediate C in the synthesis of Compound 8 of SynthesisExample 1.

¹H NMR(C₆D₆, 300 MHz) δ (ppm) 8.14 (d, 2H), 7.64 (d, 2H), 7.47 (d, 4H),7.38-7.28 (m, 6H), 7.27-7.25 (m, 8H), 7.23-7.01 (m, 161-1), 6.96 (d,2H), 2.19 (s, 6H); ¹³C NMR(C₆D₆, 100 MHz) δ (ppm) 149.0, 147.5, 142.6,142.2, 139.1, 138.9, 135.1, 132.6, 130.1, 130.7, 128.1, 127.9, 127.2,126.5, 125.9, 125.0, 124.5, 123.6, 121.8, 121.1, 119.2, 111.8, 110.8,21.5.

Compound 9 was diluted in CHCl₃ to a concentration of 0.2 mM and a UVSpectrum of the diluted Compound 9 was obtained. Maximum absorptionwavelengths were 358, 309 and 253 nm.

Td and Tg of Compound 9 were measured by performing thermal analysisusing TGA and DSC under the following conditions: N₂ atmosphere,temperatures of robin temperature to 600° C. (10° C./min)-TGA and ofroom temperature to 400° C.-DSC, and Pan Type: Pt Pan in disposable AlPan (TGA) and disposable Al pan (DSC). The measured Td was 480° C. andTg was 155° C.

A HOMO level of 5.0 eV and a LUMO level of 2.02 eV were obtained usingAC-2 that measures UV absorption spectrum and ionization potential.

Synthesis Example 3 Synthesis Compound 10

Compound 10 was synthesized through Reaction Scheme 4 below.

Synthesis of Intermediate E

3.69 g (10 mmol) of Intermediate B, 1.42 g (12 mmol) of4-aminobenzonitril, 1.44 g (15 mmol) of t-BuONa, 183 mg (0.2 mmol) ofPd₂(dba)₃, and 40 mg (0.2 mmol) of P(t-Du)₃ were dissolved in 50 ml oftoluene and the mixture was stirred at 90° C. for 3 hours.

After the reaction terminated, the resultant mixture was cooled to roomtemperature, and the resultant solution was extracted three times withdistilled water and 50 ml of diethylether. An organic layer collectedfrom the mixture was dried over MgSO₄ to evaporate the solvent. As aresult, the dried result was purified using a silica gel columnchromatography to produce 1.8 g of Intermediate E (Yield 50%).

Synthesis of Compound 10

2.2 g (Yield 86%) of Compound 10 as a yellow solid was produced in thesame manner as in Synthesis Example 1, except that Intermediate E and4,4′-dibromodiphenyl were used instead of Intermediates B and C in thesynthesis of Compound 8 of Synthesis Example 1.

¹H NMR (CDCl₃, 300 MHz) δ (ppm) 8.02 (d, 2H), 7.97 (d, 2H), 7.64-7.48(m, 14H), 7.43-7.39 (m, 10H), 7.29-7.22 (m, 8H), 7.03 (d, 4H); ¹³C NMR(CDCl₃, 100 MHz) δ (ppm) 152.1, 145.6, 141.5, 138.9, 138.2, 137.3,136.3, 133.2, 130.0, 127.9, 127.8, 127.0, 126.6, 125.8, 125.5, 124.6,122.7, 120.5, 120.2, 119.9, 119.4, 118.9, 111.2, 110.1, 101.8.

Compound 10 was diluted in CHCl₃ to a concentration of 0.2 mM and a UVSpectrum of the diluted Compound 10 was obtained. Maximum absorptionwavelengths were 304 and 238 nm.

Td, Tg and Tm of Compound 10 were measured by performing thermalanalysis using TGA and DSC under the following conditions: N₂atmosphere, temperatures of room temperature to 600° C. (10° C./min)-TGAand of room temperature to 400° C.-DSC, and Pan Type: Pt Pan indisposable Al Pan (TGA) and disposable Al pan (DSC). The measured Td was492° C., Tg was 178° C., and Tm was 263° C.

A HOMO level of 5.4 eV and a LUMO level of 2.47 eV were obtained usingAC-2 that measures UV absorption spectrum and ionization potential.

Synthesis Example 4 Synthesis Compound 11

Compound 11 was synthesized through Reaction Scheme 5 below.

Intermediate F was synthesized with a yield of 95% in the same manner asin Synthesis Example 1, except that 4-fluorophenylamine was used insteadof aniline in the synthesis of Intermediate C of Synthesis Example 1.Then, 1.8 g (Yield 84%) of Compound 11 as a yellow solid was produced inthe same manner as in Synthesis Example 1, except that Intermediate Fwas used instead of Intermediate C in the synthesis of Compound 8 ofSynthesis Example 1.

¹H NMR (C₆D₆, 300 MHz) δ (ppm) 8.05 (s, 2H), 7.68 (d, 2H), 7.48 (d, 4H),7.29-7.11 (m, 22H), 7.09-7.01 (m, 6H), 6.78 (t, 4H)

Compound 11 was diluted in CHCl₃ to a concentration of 0.2 mM and UVSpectrum of the diluted Compound 11 was obtained. Maximum absorptionwavelengths were 351, 297 and 248 nm.

Td, Tg, and Tm of Compound 11 were measured by performing thermalanalysis using TGA and DSC under the following conditions: N₂atmosphere, temperatures of room temperature to 600° C. (10° C./min)-TGAand of room temperature to 400° C.-DSC, and Pan Type: Pt Pan indisposable Al Pan (TGA) and disposable Al pan (DSC). The measured Td was464° C., Tg was 151° C., and Tm was 299° C.

A HOMO level of 5.1 eV and a LUMO level of 2.28 eV were obtained usingAC-2 that measures UV absorption spectrum and ionization potential.

Synthesis Example 5 Synthesis Compound 14

Compound 14 was synthesized through Reaction Scheme 6 below.

Intermediate G was synthesized with a yield of 90% in the same manner asin Synthesis Example 1, except that 4-aminobiphenyl was used instead ofaniline in the synthesis of Intermediate C of Synthesis Example 1. Then,3.1 g (Yield 82%) of Compound 14 as a yellow solid was produced in thesame manner as in Synthesis Example 1, except that Intermediate G wasused instead of Intermediate C in the synthesis of Compound 8 ofSynthesis Example 1.

¹H NMR (CD₂Cl₂, 300 MHz) δ (ppm) 8.02-8.01 (m, 4H), 7.65-7.56 (m, 12H),7.51-7.46 (m, 10H), 7.43-7.36 (m, 10H), 7.32-7.17 (m, 14H), ¹³C NMR(CD₂Cl₂, 100 MHz) (ppm) 148.2, 147.6, 141.8, 141.0, 140.6, 138.6, 137.9,134.5, 134.4, 130.3, 129.1, 127.9, 127.8, 127.4, 127.3, 127.0, 126.8,126.6, 126.1, 124.7, 123.5, 123.4, 123.0, 120.8, 120.3, 119.0, 111.1,110.3.

Compound 14 was diluted in CHCl₃ to a concentration of 0.2 mM and a UVSpectrum of the diluted Compound 14 was obtained. Maximum absorptionwavelength was 329 nm.

Td and Tg of Compound 14 were measured by performing thermal analysisusing TGA and DSC under the following conditions: N₂ atmosphere,temperatures of room temperature to 600° C. (10° C./min)-TGA and of roomtemperature to 400° C.-DSC, and Pan Type: Pt Pan in disposable Al Pan(TGA) and disposable Al pan (DSC). The measured Td was 533° C. and Tgwas 174° C.

A HOMO level of 5.2 eV and a LUMO level of 2.27 eV were obtained usingAC-2 that measures UV absorption spectrum and ionization potential.

Synthesis Example 6 Synthesis Compound 28

Compound 28 was synthesized through Reaction Scheme 7 below.

Intermediate H was synthesized with a yield of 80% in the same manner asin Synthesis Example 1, except that 3,6-dibromocarbozole was usedinstead of carbazole in the synthesis of intermediate A of SynthesisExample 1. Then, Intermediate I was synthesized with a yield of 85% inthe same manner as in Synthesis Example 1, except that Intermediate Hwas used instead of 4,4′-dibromodiphenyl in the synthesis ofIntermediate C of Synthesis Example 1. Then, 2.3 g (Yield 81%) ofCompound 28 as a yellow solid powder was produced in the same manner asin Synthesis Example 1, except that Intermediates B and 1 were usedinstead of Intermediates B and C in the synthesis of Compound 8 ofSynthesis Example 1.

¹H NMR (C₆D₆, 300 MHz) δ (ppm) 8.13 (s, 2H), 8.04 (s, 2H), 7.65 (d, 2H),7.39-7.31 (m, 4H), 7.27-7.22 (m, 12H), 7.19-6.99 (m, 21H), 6.82 (t, 2H);¹³C NMR(C₆D₆, 100 MHz) δ (ppm) 150.4, 142.1, 141.9, 141.8, 138.8, 138.2,138.0, 130.0, 129.9, 129.4, 128.3, 128.0, 127.8, 127.7, 127.3, 127.2,127.1, 126.4, 126.3, 125.2, 125.1, 125.0, 123.8, 121.0, 120.7, 120.4,120.2, 119.0, 117.7, 111.2, 110.9, 109.9.

Compound 28 was diluted in CHCl₃ to a concentration of 0.2 mM and UVSpectrum of the diluted Compound 28 was obtained. Maximum absorptionwavelengths were 315 and 248 nm.

Td and Tg of Compound 28 were measured by performing thermal analysisusing TGA and DSC under the following conditions: N₂ atmosphere,temperatures of room temperature to 600° C. (10° C./min)-TGA and of roomtemperature to 400° C.-DSC, and Pan Type: Pt Pan in disposable Al Pan(TGA) and disposable Al pan (DSC). The measured Td was 460° C. and Tgwas 175° C.

A HOMO level of 5.0 eV and a LUMO level of 2.09 eV were obtained usingAC-2 that measures UV absorption spectrum and ionization potential.

Synthesis Example 7 Synthesis Compound 35

Compound 35 was synthesized through Reaction Scheme 8 below.

Synthesis of Intermediate J

0.316 g (0.856 mmol) of Intermediate B, 0.142 g (1.2 mmol) of4-aminobenzonitril were dissolved in 5 ml of toluene and 0.144 g (1.5mmol) of t-BuONa, 0.018 g (0.02 mmol) of Pd(dba)₂, and 0.004 to 0.006 g(0.02 to 0.03 mmol) of (t-Bu)₃P were added thereto. The mixture wasstirred at 80° C. for 5 hours. The resultant solution was extractedthree times with 20 ml of ethylether. An organic layer collected fromthe mixture was dried over MgSO₄ to evaporate the solvent. As a result,the dried result was purified using a silica gel column chromatographyto produce 0.218 g of Intermediate J (Yield 71%).

Synthesis of Compound 35

0.221 g (0.614 mmol) of Intermediate J, 0.332 g (0.9 mmol) ofIntermediate B were dissolved in 10 ml of toluene and 0.144 g (1.5 mmol)of t-BuONa, 0.018 g (0.02 mmol) of Pd(dba)₂, and 0.004 to 0.006 g (0.02to 0.03 mmol) of (t-Bu)₃P were added thereto. The mixture was stirred at90° C. for 6 hours. The resultant solution was extracted three timeswith 30 ml of ethylether. An organic layer collected from the mixturewas dried over MgSO₄ to evaporate the solvent. As a result, the driedresult was purified using a silica gel column chromatography to produce0.236 g of Compound 35 (Yield 64%). Compound 35 was identified by¹H-NMR.

¹H-NMR (CDCl₃, 400 MHz) δ (ppm) 8.05 (d, 2H), 8.03 (dd, 2H), 7.58 (m,8H), 7.47 (m, 2H), 7.39 (m, 8H), 7.33 (dd, 2H), 7.24 (m, 2H), 6.94 (d,2H).

Synthesis Example 8 Synthesis Compound 56

Compound 56 was synthesized through Reaction Scheme 9 below.

Synthesis of Intermediate K

13 g (53 mmol) of 2-bromofluorene was dissolved in 60 ml of acetic acid.The reaction mixture was set 0° C., and 60 g (200 mmol) of sodiumdichromate was gradually added thereto. After 12 hours, 200 ml ofdistilled water was added thereto and the reaction mixture wassufficiently stirred. The produced yellow solid was filtered and driedto to produce 10 g of Intermediate K (Yield 78%).

Synthesis of Intermediate L

8 g (31.6 mmol) of Intermediate K was dissolved in 60 ml of THF. Thetemperature of the reaction mixture was set to −78° C., and 38 ml (38mmol) of 1 M phenylmagnesium bromide was gradually added thereto. After2 hours, the temperature was set to room temperature and stirred for 5hours. The reaction mixture was diluted in 50 ml of ammonium chloridesolution and extracted three times with 40 ml of ethylacetate. Anorganic layer collected from the mixture was dried over MgSO₄ toevaporate the solvent. As a result, the dried result was purified usinga silica gel column chromatography to produce 10 g of Intermediate L(Yield 95%). Intermediate L was identified by ¹H-NMR

¹H NMR (CDCl₃, 400 MHz) δ (ppm) 7.64 (d, 1H), 7.54-7.47 (m, 2H), 7.44(d, 1H), 7.39-7.33 (m, 3H), 7.30-7.23 (m, 5H), 2.46 (s, 1H)

Synthesis of Intermediate M

10 g (30 mmol) of Intermediate L was dissolved in 60 ml of benzene. 2.4ml (45 mmol) of sulfuric acid diluted in a small amount of benzene wasadded thereto. The reaction mixture was stirred at 80° C. for 5 hours.After the benzene was evaporated, 1 N NaOH was added to the reactionsolution to adjust the pH of the reaction solution to 7. Then, theresultant solution was extracted three times with 40 ml of ethylacetate.An organic layer collected from the mixture was dried over MgSO₄ toevaporate the solvent. As a result, the dried result was purified usinga silica gel column chromatography to produce 6 g of Intermediate M(Yield 50%).

Synthesis of Intermediate O

340 mg (0.856 mmol) of Intermediate M, 142 mg (1.2 mmol) of4-aminobenzonitril were dissolved in 5 ml of toluene and 0.144 g (1.5mmol) of t-BuONa, 0.018 g (0.02 mmol) of Pd(dba)₂, and 0.004 to 0.006 g(0.02 to 0.03 mmol) of (t-Bu)₃P were added thereto. The mixture wasstirred at 80° C. for 5 hours. The resultant solution was extractedthree times with 20 ml of ethylether. An organic layer collected fromthe mixture was dried over MgSO₄ to evaporate the solvent. As a result,the dried result was purified using a silica gel column chromatographyto produce 0.27 g of Intermediate O (Yield 73%).

Synthesis of Compound 56

267 mg (0.614 mmol) of Intermediate 0, 0.332 g (0.9 mmol) ofIntermediate B (refer to Synthesis Example 1) were dissolved in 10 ml oftoluene and 0.144 g (1.5 mmol) of t-BuONa, 0.018 g (0.02 mmol) ofPd(dba)₂, and 0.004 to 0.006 g (0.02 to 0.63 mmol) of (t-Bu)₃P wereadded thereto. The mixture was stirred at 90° C. for 6 hours. Theresultant solution was extracted three times with 30 ml of ethylether.An organic layer collected from the mixture was dried over MgSO₄ toevaporate the solvent. As a result, the dried result was purified usinga silica gel column chromatography to produce 0.236 g of Compound 56(Yield 57%). Compound 56 was identified by ¹H-NMR.

¹H NMR (CDCl₃, 400 MHz) δ (ppm) 7.97 (d, 1H), 7.90 (d, 1H), 7.69 (d,1H), 7.65 (d, 1H), 7.60 (d, 2H), 7.56 (dd, 2H), 7.48 (m, 1H), 7.40 (d,2H), 7.35 (m, 6H), 7.24 (m, 3H), 7.16 (m, 10H), 7.11 (dd, 1H), 6.93 (d,2H)

Example 1

An aluminium and ITO glass (SDI Co., Ltd.) substrate (1,300 Å) was cutinto pieces of 50 mm×50 mm×0.7 mm in size, followed by ultrasoniccleaning in isopropyl alcohol and deionized water (5 minutes for each)and then UV/ozone cleaned (30 minutes) to produce a reflectiveelectrode.

Then, Compound 8 was deposited on the reflective electrode to form a HILwith a thickness of 1,200 Å, and NPB was deposited on the HIL to form aHTL with a thickness of 300 Å.

IDE 140 (Idemitsu Corporation) as a blue fluorescent host and IDE 105(Idemitsu Corporation) as a blue fluorescent dopant were deposited atthe same time in a weight ratio of 98:2 on the HTL to form a blue EMLwith a thickness of 300 Å. Then, Balq was deposited on the blue EML toform a HBL with a thickness of 50 Å. Alq3 was deposited on the HBL toform an ETL with a thickness of 250 Å. LiF was deposited on the ETL toform an EIL with a thickness of 3 Å, and then Mg:Ag was deposited on theEIL to form a semitransparent electrode with a thickness of 180 Å. As aresult, an organic light emitting device was manufactured.

At a driving voltage of 5.5 V, the current density of the organic lightemitting device was 23.0 mA/cm², the luminance was 1,179 cd/m², thecolor coordinates were (0.113, 0.130), and the light emitting efficiencywas 5.13 cd/A.

Example 2

An organic light emitting device was manufactured in the same manner asin Example 1 except that Compound 9 was used instead of Compound 8 inthe formation of a HIL.

At a driving voltage of 5.5 V, the current density of the organic lightemitting device was 20.1 mA/cm², the luminance was 1,021 cd/m², thecolor coordinates were (0.113, 0.120), and the light emitting efficiencywas 5.10 cd/A.

Example 3

An organic light emitting device was manufactured in the same manner asin Example 1 except that IDE 406 (Idemitsu Corporation) was used insteadof Compound 8 in the formation of a HIL.

At a driving voltage of 5.5 V, the current density of the organic lightemitting device was 46.52 mA/cm², the luminance was 784 cd/m², the colorcoordinates were (0.113, 0.125), and the light emitting efficiency was4.74 cd/A.

Example 4

An organic light emitting device was manufactured in the same manner asin Example 1 except that Li273 (Sensient, Germany) was used instead ofCompound 8 in the formation of a HIL.

At a driving voltage of 5.5 V, the current density of the organic lightemitting device was 17.43 mA/cm², the luminance was 695 cd/m², the colorcoordinates were (0.122, 0.110), and the light emitting efficiency was3.98 cd/A.

Example 5

An organic light emitting device was manufactured in the same manner asin Example 1 except that HI102 (UDC, U.S.A.) was used instead ofCompound 8 in the formation of a HIL.

At a driving voltage of 5.5 V, the current density of the organic lightemitting device was 0.67 mA/cm², the luminance was 1.2 cd/m², the colorcoordinates were (0.112, 0.154), and the light emitting efficiency was0.18 cd/A.

Example 6

An organic light emitting device was manufactured in the same manner asin Example 1 except that ELM180 (ELM, Korea) was used instead ofCompound 8 in the formation of a HIL.

At a driving voltage of 5.5 V, the current density of the organic lightemitting device was 2.55 mA/cm², the brightness was 52 cd/m², the colorcoordinates were (0.124, 0.105), and the light emitting efficiency was2.04 cd/A.

Referring to Examples 1 through 6, when Compound 8 or 9 was used to formthe HIL or the thickness of the HIL was controlled according to anembodiment of the present invention, the hole injecting capabilityincreased, and thus the current densities and the current efficienciesof the organic light emitting devices increased at the same drivingvoltage and luminance increased. The results of the current efficienciesat the same voltage are illustrated in FIG. 3.

The evaluation results for the luminance changes and driving voltagechanges of the organic light emitting devices according to Examples 1and 3 are shown in FIGS. 4 and 5. An accelerated life test was performedto measure luminance changes of the organic light emitting devices ofExamples 1 and 3. The luminances were measure after 200 hours at 4,000cd/m² as shown in FIG. 4. The luminance of the organic light emittingdevice of Example 1 after 200 hours at 4,000 cd/m² was 90.2% of theinitial luminance, and the 327 luminance of the organic light emittingdevice of Example 3 after 200 hours at 4,000 cd/m² was 86.2% of theinitial luminance. FIG. 5 illustrates the accelerated life test resultsof the driving voltage changes after 400 hours at 4,000 cd/m². Thedriving voltage of the organic light emitting device of Example 1increased by 0.45 V and the driving voltage of the organic lightemitting device of Example 3 increased by 1.65 V. Referring to FIG. 5,the organic light emitting device of Example 1 has low power consumptionand low driving voltage.

Example 7

An organic light emitting device was manufactured in the same manner asin Example 1 except that Compound 11 was deposited on the electrode toform a HIL with a thickness of 1600 Å, and CBP and Ir(ppy)₃ as greenlight emitting materials were deposited on the HTL to form a green EMLwith a thickness of 300 Å instead of the blue EML.

At a driving voltage of 5 V, the current density of the organic lightemitting device was 7.5 mA/cm², the luminance was 2220 cd/m², the colorcoordinates were (0.244, 0.71), and the light emitting efficiency was29.6 cd/A.

Example 8

An organic light emitting device was manufactured in the same manner asin Example 7 except that IDE 406 (Idemitsu Corporation) was used insteadof Compound 11 in the formation of a HIL.

At a driving voltage of 5 V, the current density of the organic lightemitting device was 7.86 mA/cm², the luminance was 1,900 cd/m², thecolor coordinates were (0.246, 0.691), and the light emitting efficiencywas 23.9 cd/A.

The current efficiencies of Examples 7 and 8 are shown in FIG. 6.

Example 9

An organic light emitting device was manufactured in the same manner asin Example 1 except that Compound 14 was deposited on the electrode toform a HIL with a thickness of 2000 Å, and CBP and BPTIr as red lightemitting materials were deposited on the HTL to form a red EML with athickness of 300 Å instead of the blue EML.

At a driving voltage of 5 V, the current density of the organic lightemitting device was 11.8 mA/cm², the luminance was 1,534 cd/m², thecolor coordinates were (0.687, 0.310), and the light emitting efficiencywas 13.0 cd/A.

Example 10

An organic light emitting device was manufactured in the same manner asin Example 9 except that IDE 406 (Idemitsu Corporation) was used insteadof Compound 14 in the formation of a HIL.

At a driving voltage of 5 V, the current density of the organic lightemitting device was 13.3 mA/cm², the brightness was 1328 cd/m², thecolor coordinates were (0.692, 0.306), and the light emitting efficiencywas 9.98 cd/A.

The current efficiencies of Examples 9 and 10 are shown in FIG. 7.

The driving voltage, efficiency, and color purity characteristics of theorganic light emitting devices of Examples 1-10 were evaluated using anIVL measuring device (PhotoResearch PR650, Keithley 238).

Example 11

An organic light emitting device including red, s green, and blue EMLswas manufactured as follows.

A substrate having a thin film transistor was prepared, and a firstelectrode composed of Al was formed in a stripe shape with a thicknessof 1000 Å. Here, the first electrode was electrically connected to asource electrode or a drain electrode of the thin film transistor formedon the substrate.

Red, green and blue sub-pixel defining layers which define regions inwhich the red, green, and blue EMLs will be formed were formed on thefirst electrode using a silicon oxide. Compound 8 was deposited on theregions in which the red, green and blue EML will be formed to form aHIL. Compound 8 was deposited on the region in which the red EML will beformed to a thickness of 2000 Å, on the region in which the green EMLwill be formed a thickness of 1600 Å, and on the region in which theblue EML will be formed to a thickness of 1200 Å to form the HIL. Then,NPB was deposited on the HIL to form a HTL with a thickness of 300 Å.

CBP and BPTIr as red light emitting materials were deposited on the HTLto form a red EML with a thickness of 300 Å, CBP and Irppy as greenlight emitting materials were deposited on the HTL to form a green EMLwith a thickness of 300 Å, and IDE 140 (Idemitsu Corporation) and IDE105 (Idemitsu Corporation) as blue light emitting materials weredeposited on the HTL to form a blue EML with a thickness of 150 Å.

Then, Balq was deposited on the red, green and blue EMLs to form a HBLwith a thickness of 50 Å. Alq3 was deposited on the HBL to form an ETLwith a thickness of 250 Å. LiF was deposited on the ETL to form an EILwith a thickness of 3 Å, and then Mg:Ag was deposited on the EIL to forma semitransparent electrode with a thickness of 180 Å. As a result, anorganic light emitting device including the red, green, and blue EMLswas manufactured.

The efficiency and the color coordinates of the organic light emittingdevice of Example 11 were measured in the same manner as in Examples 1through 10. The results are shown in Table 1.

TABLE 1 x Efficiency (cd/A) Color Coordinate y Color Coordinate Red EML13.4 0.68 0.32 Green EML 29.9 0.22 0.73 Blue EML 2.9 0.14 0.06

As shown in Table 1, each EML of the organic light emitting device ofExample 11 exhibited excellent efficiency and color purity. Theefficiency of white light comprising a mixture of red, green, and bluelight in the organic light emitting device of Example 11 was 13.0 cd/Aat a luminance of 150 cd/m² when 40% of the device was operating, andpower consumption was 180 mW. The efficiency and color puritycharacteristics of the organic light emitting device of Example 11 wereevaluated using an IVL measuring device (PhotoResearch PR650, Keithley238) and the power consumption was calculated.

Example 12

An organic light emitting device was manufactured in the same manner asin Example 11 except that IDE 406 (Idemitsu Corporation) was usedinstead of Compound 8 to form a HIL. The efficiency and the colorcoordinates of the organic light emitting device of Example 12 are shownin Table 2.

TABLE 2 x Efficiency (cd/A) Color Coordinate y Color Coordinate Red EML12.1 0.67 0.32 Green EML 25.4 0.23 0.73 Blue EML 2.24 0.14 0.06

As shown in Table 2, each EML of the organic light emitting device ofExample 12 exhibited excellent efficiency and color purity. Theefficiency of white light comprising a mixture of red, green, and bluelight in the organic light emitting device of Example 12 was 11.0 cd/Aat a brightness of 150 cd/m² when 40% of the device was operating, andpower consumption was 220 mW. The efficiency and color puritycharacteristics of the organic light emitting device of Example 12 wereevaluated using an IVL measuring device (PhotoResearch PR650, Keithley238) and the power consumption was calculated.

Comparative Example 1

A substrate having a thin film transistor was prepared, and a firstelectrode composed of A1 was formed in a stripe shape with a thicknessof 1000 Å. Here, the first electrode was electrically connected to asource electrode or a drain electrode of the thin film transistor formedon a lower portion of the substrate.

Red, green and blue pixel defining layers which define regions in whichred, green, and blue emission layers will be formed were formed on thepixel electrode using a silicon oxide. M-TDATA was deposited on theregions in which red, green and blue emission layers will be formed forma HIL with a thickness of 1000 Å. Then NPB was deposited on the HIL toform a HTL with a thickness of 400 Å. In addition, NPB was furtherdeposited over the region in which green EML will be formed to athickness of 400 Å using a photomask. NPB was further deposited over theregion in which red EML will be formed to a thickness of 800 Å. As aresult, HTL having total thickness of 1200 Å in the region in which redEML will be formed, total thickness of 800 Å in the region in whichgreen EML will be formed an to total thickness of 400 Å in the region inwhich blue EML will be formed.

CBP and BPTIr as red light emitting materials were deposited on the redHTL to form a red EML with a thickness of 300 Å, CBP and Irppy as greenlight emitting materials were deposited on the green HTL to form a greenEML with a thickness of 300 Å, and IDE 140 (Idemitsu Corporation) andIDE 105 (Idemitsu Corporation) as blue light emitting materials weredeposited on the blue HTL to form a blue EML with a thickness of 150 Å.

Then, Balq was deposited on the red, green and blue EMLs to form a HBLwith a thickness of 50 Å. Alq3 was deposited on the HBL to form an ETLwith a thickness of 250 Å. LiF was deposited on the ETL to form an EILwith a thickness of 3 Å, and then Mg:Ag was deposited on the EIL to forma semitransparent electrode with a thickness of 180 Å. As a result, anorganic light emitting device including the red, green, and blue EMLswas manufactured.

The efficiency and the color coordinates of the organic light emittingdevice of Comparative Example 1 are shown in Table 3.

TABLE 3 x Efficiency (cd/A) Color Coordinate y Color Coordinate Red EML5.39 0.67 0.32 Green EML 24.45 0.21 0.72 Blue EML 1.40 0.14 0.06

As shown in Table 3, the organic light emitting device of Example 11having a material used to form a HIL according to an embodiment of thepresent invention and the organic light emitting device of Example 12having the thickness of the HIL according to an embodiment of thepresent invention exhibited greater efficiency and color purity than theorganic light emitting device of Comparative Example 1.

An organic light emitting device according to the present inventionincludes an organic layer containing one of the compounds represented byFormulae 1, 2, and 3 between a pair of electrodes capable of generatingresonance during the operation of the device; and/or a hole injectionlayer having the thickness range described above between the pair ofelectrodes. The organic light emitting device of the present inventionhas low driving voltage, excellent current density, high brightness,excellent color purity, high efficiency, and long lifetime. Inparticular, the organic light emitting device of the present inventionhas excellent lifetime property. A flat panel display device havingenhanced reliability can be obtained by employing the organic lightemitting device of the present invention.

While the present invention has been particularly shown and describedwith reference to exemplary embodiments thereof, it will be understoodby those of ordinary skill in the art that various changes in form anddetails may be made therein without departing from the spirit and scopeof the present invention as defined by the following claims.

What is claimed is:
 1. An organic light emitting device, comprising: asubstrate; a first electrode; a second electrode, one of the firstelectrode and the second electrode being a reflective electrode, theother being a semitransparent or transparent electrode; and an organiclayer interposed between the first electrode and the second electrode,the organic layer comprising: an emission layer comprising a redemission region, a green emission region and a blue emission region; anda layer comprising at least one compound selected from the groupconsisting of compounds represented by Formula 1, the layer having afirst region formed under the red emission region, a second regionformed under the green emission region and a third region formed underthe blue emission region, the thickness of the first region being in therange of 1,600 to 2,200 Å, the thickness of the second region being inthe range of 1,400 to 1,800 Å, the thickness of the third region beingin the range of 1,000 to 1,400 Å, resonance occurring between the firstelectrode and the second electrode during an operation of the organiclight emitting device and the layer being between the first electrodeand the emission layer:

X being one selected from the group consisting of a substituted orunsubstituted C₁-C₃₀ alkylene group, a substituted or unsubstitutedC₂-C₃₀ alkenylene group, a substituted or unsubstituted C₆-C₃₀ arylenegroup, a substituted or unsubstituted C₂-C₃₀ heteroarylene group, and asubstituted or unsubstituted C₂-C₃₀ hetero ring, each R₁, each R₂, andeach R₃ independently being one selected from the group consisting of ahydrogen atom, a substituted or unsubstituted C₁-C₃₀ alkyl group, asubstituted or unsubstituted C₁-C₃₀ alkoxy group, a substituted orunsubstituted C₆-C₃₀ aryl group, a substituted or unsubstituted C₆-C₃₀aryloxy group, a substituted or unsubstituted C₂-C₃₀ hetero ring, asubstituted or unsubstituted C₅-C₃₀ polycyclic condensed ring, a hydroxygroup, a cyano group, and a substituted or unsubstituted amino group,wherein two or more of R₁, R₂, and R₃ can be optionally bound with oneanother to form a saturated or unsaturated carbon ring, and each Ar₁independently being a substituted or unsubstituted C₆-C₃₀ aryl group ora substituted or unsubstituted C₂-C₃₀ heteroaryl group.
 2. The organiclight emitting device of claim 1, wherein the compound represented byFormula 1 comprises a compound represented by Formula 1a:

each R₁, each R₂, and each R₃ independently being one selected from thegroup consisting of a hydrogen atom, a substituted or unsubstitutedC₁-C₃₀ alkyl group, a substituted or unsubstituted C₁-C₃₀ alkoxy group,a substituted or unsubstituted C₆-C₃₀ aryl group, a substituted orunsubstituted C₆-C₃₀ aryloxy group, a substituted or unsubstitutedC₂-C₃₀ hetero ring, a substituted or unsubstituted C₅-C₃₀ polycycliccondensed ring, a hydroxy group, a cyano group, and a substituted orunsubstituted amino group, wherein two or more of R₁, R₂ and R₃ can beoptionally bound with one another to form a saturated or unsaturatedcarbon ring, and each Q₁ independently being one selected from the groupconsisting of a hydrogen atom, a cyano group, a fluorine atom, asubstituted or unsubstituted C₁-C₃₀ alkyl group, a substituted orunsubstituted C₆-C₃₀ aryl group, a substituted or unsubstituted C₂-C₃₀hetero ring, and a substituted or unsubstituted amino group.
 3. Theorganic light emitting device of claim 1, wherein the compoundrepresented by Formula 1 comprises a compound represented by Formula 1b:

each R₁, each R₂, and each R₃ independently being one selected from thegroup consisting of a hydrogen atom, a substituted or unsubstitutedC₁-C₃₀ alkyl group, a substituted or unsubstituted C₁-C₃₀ alkoxy group,a substituted or unsubstituted C₆-C₃₀ aryl group, a substituted orunsubstituted C₆-C₃₀ aryloxy group, a substituted or unsubstitutedC₂-C₃₀ hetero ring, a substituted or unsubstituted C₅-C₃₀ polycycliccondensed ring, a hydroxy group, a cyano group, and a substituted orunsubstituted amino group, wherein two or more of R₁, R₂ and R₃ can beoptionally bound with one another to form a saturated or unsaturatedcarbon ring, and each Q₂ being one selected from the group consisting ofa hydrogen atom, a cyano group, a fluorine atom, a substituted orunsubstituted C₁-C₃₀ alkyl group, a substituted or unsubstituted C₆-C₃₀aryl group, a substituted or unsubstituted C₂-C₃₀ hetero ring, and asubstituted or unsubstituted amino group.
 4. The organic light emittingdevice of claim 1, wherein the compounds represented by Formula 1 areCompounds 1 through 27:


5. The organic light emitting device of claim 1, wherein the compoundsrepresented by Formula 1 are Compounds 8 through 11 and 14:


6. The organic light emitting device of claim 1, wherein the layercomprising said at least one compound selected from the group ofcompounds represented by Formula 1 is one of a hole injection layer, ahole transport layer, and a single layer having hole injecting andtransporting properties.
 7. The organic light emitting device of claim1, wherein the layer comprising said at least one compound selected fromthe group of compounds represented by Formula 1 is a hole injectionlayer.
 8. The organic light emitting device of claim 7, wherein theemission layer comprises the red emission region, and the thickness ofthe first region of the hole injection layer formed under the redemission region is in the range of 1,600 to 2,200 Å.
 9. The organiclight emitting device of claim 7, wherein the emission layer comprisesthe green emission region, and the thickness of the second region of thehole injection layer formed under the green emission region is in therange of 1,400 to 1,800 Å.
 10. The organic light emitting device ofclaim 7, wherein the emission layer comprises the blue emission region,and the thickness of the third region of the hole injection layer formedunder the blue emission region is in the range of 1,000 to 1,400 Å. 11.The organic light emitting device of claim 7, wherein the emission layercomprises the red emission region, the blue emission region and thegreen emission region; the hole injection layer comprises the firstregion formed under the red emission region, the second region formedunder the green emission region and the third region formed under theblue emission region; and the thickness of the first region is in therange of 1,600 to 2,200 Å, the thickness of the second region is in therange of 1,400 to 1,800 Å, and the thickness of the third region is inthe range of 1,000 to 1,400 Å.
 12. The organic light emitting device ofclaim 7, wherein the organic layer further comprises a hole transportlayer.
 13. The organic light emitting device of claim 12, wherein theemission layer comprises the red emission region, and the totalthickness of a region of the hole transport layer and the hole injectionlayer formed under the red emission region is in the range of 2,000 to2,400 Å.
 14. The organic light emitting device of claim 13, wherein thethickness of the region of the hole injection layer formed under the redemission region is in the range of 1,600 to 2,200 Å.
 15. The organiclight emitting device of claim 12, wherein the emission layer comprisesthe green emission region, and the total thickness of a region of thehole transport layer and the hole injection layer formed under the greenemission region is in the range of 1,600 to 2,000 Å.
 16. The organiclight emitting device of claim 15, wherein the thickness of the regionof the hole injection layer formed under the green emission region is inthe range of 1,400 to 1,800 Å.
 17. The organic light emitting device ofclaim 12, wherein the emission layer comprises the blue emission region,and the total thickness of a region of the hole transport layer and thehole injection layer formed under the blue emission region is in therange of 1,200 to 1,600 Å.
 18. The organic light emitting device ofclaim 17, wherein the thickness of the region of the hole injectionlayer formed under the blue emission region is in the range of 1,000 to1,400 Å.
 19. A flat panel display device comprising the organic lightemitting device of claim
 1. 20. The flat panel display of claim 19,wherein the first electrode of the organic light emitting device iselectrically connected to a source electrode or a drain electrode of athin film transistor.
 21. The organic light emitting device of claim 1,the first electrode being disposed on the substrate and being areflective electrode, the second electrode being a semitransparent ortransparent electrode, and light generated in the organic layer passingthrough the second electrode.
 22. An organic light emitting device,comprising: a substrate; a first electrode; a second electrode, one ofthe first electrode and the second electrode being a reflectiveelectrode, the other being a semitransparent or transparent electrode;and an organic layer interposed between the first electrode and thesecond electrode, the organic layer comprising: an emission layercomprising a red emission region, a green emission region and a blueemission region; and a layer comprising at least one compound selectedfrom the group consisting of compounds represented by Formula 2, thelayer having a first region formed under the red emission region, asecond region formed under the green emission region and a third regionformed under the blue emission region, the thickness of the first regionbeing in the range of 1,600 to 2,200 Å, the thickness of the secondregion being in the range of 1,400 to 1,800 Å, the thickness of thethird region being in the range of 1,000 to 1,400 Å, resonance occurringbetween the first electrode and the second electrode during an operationof the organic light emitting device and the layer being between thefirst electrode and the emission layer:

each R₄ and each R₅ independently being one selected from the groupconsisting of a hydrogen atom, a substituted or unsubstituted C₁-C₃₀alkyl group, a substituted or unsubstituted C₁-C₃₀ alkoxy group, asubstituted or unsubstituted C₆-C₃₀ aryl group, a substituted orunsubstituted C₆-C₃₀ aryloxy group, a substituted or unsubstitutedC₂-C₃₀ hetero ring, a substituted or unsubstituted C₅-C₃₀ polycycliccondensed ring, a hydroxy group, a cyano group, and a substituted orunsubstituted amino group, wherein R₄ and R₅ can be optionally boundwith one another to form a saturated or unsaturated carbon ring, andeach Ar₂ independently being a substituted or unsubstituted C₆-C₃₀ arylgroup or a substituted or unsubstituted C₂-C₃₀ heteroaryl group.
 23. Theorganic light emitting device of claim 22, wherein the compoundrepresented by Formula 2 comprises a compound represented by Formula 2a:

R₄ and R₅ each independently being one selected from the groupconsisting of a hydrogen atom, a substituted or unsubstituted C₁-C₃₀alkyl group, a substituted or unsubstituted C₁-C₃₀ alkoxy group, asubstituted or unsubstituted C₆-C₃₀ aryl group, a substituted orunsubstituted C₆-C₃₀ aryloxy group, a substituted or unsubstitutedC₂-C₃₀ hetero ring, a substituted or unsubstituted C₅-C₃₀ polycycliccondensed ring, a hydroxy group, a cyano group, and a substituted orunsubstituted amino group, wherein R₄, and R₅ can be optionally boundwith one another to form a saturated or unsaturated carbon ring, and Q₃being one selected from the group consisting of a hydrogen atom, a cyanogroup, a fluorine atom, a substituted or unsubstituted C₁-C₃₀ alkylgroup, a substituted or unsubstituted C₆-C₃₀ aryl group, a substitutedor unsubstituted C₂-C₃₀ hetero ring, and a substituted or unsubstitutedamino group.
 24. The organic light emitting device of claim 22, whereinthe compounds represented by Formula 2 are Compounds 28 through 45:


25. The organic light emitting device of claim 22, wherein the compoundrepresented by Formula 2 is Compound 28:


26. The organic light emitting device of claim 22, wherein the layercomprising said at least one compound selected from the group ofcompounds represented by Formula 2 is one of a hole injection layer, ahole transport layer, and a single layer having hole injecting andtransporting properties.
 27. The organic light emitting device of claim22, wherein the layer comprising said at least one compound selectedfrom the group of compounds represented by Formula 2 is a hole injectionlayer.
 28. The organic light emitting device of claim 27, wherein theemission layer comprises the red emission region, and the thickness ofthe first region of the hole injection layer formed under the redemission region is in the range of 1,600 to 2,200 Å.
 29. The organiclight emitting device of claim 27, wherein the emission layer comprisesthe green emission region, and the thickness of the second region of thehole injection layer formed under the green emission region is in therange of 1,400 to 1,800 Å.
 30. The organic light emitting device ofclaim 27, wherein the emission layer comprises the blue emission region,and the thickness of the third region of the hole injection layer formedunder the blue emission region is in the range of 1,000 to 1,400 Å. 31.The organic light emitting device of claim 27, wherein the emissionlayer comprises the red emission region, the blue emission region andthe green emission region; the hole injection layer comprises the firstregion formed under the red emission region, the second region formedunder the green emission region and the third region formed under theblue emission region; and the thickness of the first region is in therange of 1,600 to 2,200 Å, the thickness of the second region is in therange of 1,400 to 1,800 Å, and the thickness of the third region is inthe range of 1,000 to 1,400 Å.
 32. The organic light emitting device ofclaim 27, wherein the organic layer further comprises a hole transportlayer.
 33. The organic light emitting device of claim 32, wherein theemission layer comprises the red emission region, and the totalthickness of a region of the hole transport layer and the hole injectionlayer formed under the red emission region is in the range of 2,000 to2,400 Å.
 34. The organic light emitting device of claim 33, wherein thethickness of the region of the hole injection layer formed under the redemission region is in the range of 1,600 to 2,200 Å.
 35. The organiclight emitting device of claim 32, wherein the emission layer comprisesthe green emission region, and the total thickness of a region of thehole transport layer and the hole injection layer formed under the greenemission region is in the range of 1,600 to 2,000 Å.
 36. The organiclight emitting device of claim 35, wherein the thickness of the regionof the hole injection layer formed under the green emission region is inthe range of 1,400 to 1,800 Å.
 37. The organic light emitting device ofclaim 32, wherein the emission layer comprises the blue emission region,and the total thickness of a region of the hole transport layer and thehole injection layer formed under the blue emission region is in therange of 1,200 to 1,600 Å.
 38. The organic light emitting device ofclaim 37, wherein the thickness of the region of the hole injectionlayer formed under the blue emission region is in the range of 1,000 to1,400 Å.
 39. A flat panel display device comprising the organic lightemitting device of claim
 22. 40. The flat panel display of claim 39,wherein the first electrode of the organic light emitting device iselectrically connected to a source electrode or a drain electrode of athin film transistor.
 41. The organic light emitting device of claim 22,the first electrode being disposed on the substrate and being areflective electrode, the second electrode being a semitransparent ortransparent electrode, and light generated in the organic layer passingthrough the second electrode.
 42. An organic light emitting device,comprising: a substrate; a first electrode; a second electrode, one ofthe first electrode and the second electrode being a reflectiveelectrode, the other being a semitransparent or transparent electrode;and an organic layer interposed between the first electrode and thesecond electrode, the organic layer comprising: an emission layercomprising a red emission region, a green emission region and a blueemission region; and a layer comprising at least one compound selectedfrom the group consisting of compounds represented by Formula 3, thelayer having a first region formed under the red emission region, asecond region formed under the green emission region and a third regionformed under the blue emission region, the thickness of the first regionbeing in the range of 1,600 to 2,200 Å, the thickness of the secondregion being in the range of 1,400 to 1,800 Å, the thickness of thethird region being in the range of 1,000 to 1,400 Å, resonance occurringbetween the first electrode and the second electrode during an operationof the organic light emitting device and the layer being between thefirst electrode and the emission layer:

each R₆, each R₇, and each R₈ independently being one selected from thegroup consisting of a hydrogen atom, a substituted or unsubstitutedC₁-C₃₀ alkyl group, a substituted or unsubstituted C₁-C₃₀ alkoxy group,a substituted or unsubstituted C₆-C₃₀ aryl group, a substituted orunsubstituted C₆-C₃₀ aryloxy group, a substituted or unsubstitutedC₂-C₃₀ hetero ring, a substituted or unsubstituted C₅-C₃₀ polycycliccondensed ring, a hydroxy group, a cyano group, and a substituted orunsubstituted amino group, wherein two or more of R₆, R₇, and R₈ can beoptionally bound with one another to form a saturated or unsaturatedcarbon ring, each Ar_(a) independently being a substituted orunsubstituted C₆-C₃₀ aryl group or a substituted or unsubstituted C₂-C₃₀heteroaryl group, each Y independently being one selected from the groupconsisting of a substituted or unsubstituted C₁-C₃₀ alkyl group, asubstituted or unsubstituted C₆-C₃₀ aryl group, and a substituted orunsubstituted C₂-C₃₀ hetero ring, and each n independently being aninteger from 0 to
 5. 43. The organic light emitting device of claim 42,wherein the compound represented by Formula 3 comprises a compoundrepresented by Formula 3a:

R₆, R₇ and R₈ independently being one selected from the group consistingof a hydrogen atom, a substituted or unsubstituted C₁-C₃₀ alkyl group, asubstituted or unsubstituted C₁-C₃₀ alkoxy group, a substituted orunsubstituted C₆-C₃₀ aryl group, a substituted or unsubstituted C₆-C₃₀aryloxy group, a substituted or unsubstituted C₂-C₃₀ hetero ring, asubstituted or unsubstituted C₅-C₃₀ polycyclic condensed ring, a hydroxygroup, a cyano group, and a substituted or unsubstituted amino group,wherein two or more of R₆, R₇ and R₈ can be optionally bound with oneanother to form a saturated or unsaturated carbon ring, and Q₄ being oneselected from the group consisting of a hydrogen atom, a cyano group, afluorine atom, a substituted or unsubstituted C₁-C₃₀ alkyl group, asubstituted or unsubstituted C₆-C₃₀ aryl group, a substituted orunsubstituted C₂-C₃₀ hetero ring, and a substituted or unsubstitutedamino group.
 44. The organic light emitting device of claim 42, whereinthe compounds represented by Formula 3 are Compounds 46 through 62:


45. The organic light emitting device of claim 42, wherein the compoundrepresented by Formula 3 is Compound 56:


46. The organic light emitting device of claim 42, wherein the layercomprising said at least one compound selected from the group ofcompounds represented by Formula 3 is one of a hole injection layer, ahole transport layer, and a single layer having hole injecting andtransporting properties.
 47. The organic light emitting device of claim42, wherein the layer comprising said at least one compound selectedfrom the group of compounds represented by Formula 3 is a hole injectionlayer.
 48. The organic light emitting device of claim 47, wherein theemission layer comprises the red emission region, and the thickness ofthe first region of the hole injection layer formed under the redemission region is in the range of 1,600 to 2,200 Å.
 49. The organiclight emitting device of claim 47, wherein the emission layer comprisesthe green emission region, and the thickness of the second region of thehole injection layer formed under the green emission region is in therange of 1,400 to 1,800 Å.
 50. The organic light emitting device ofclaim 47, wherein the emission layer comprises the blue emission region,and the thickness of the third region of the hole injection layer formedunder the blue emission region is in the range of 1,000 to 1,400 Å. 51.The organic light emitting device of claim 47, wherein the emissionlayer comprises the red emission region, the blue emission region andthe green emission region; the hole injection layer comprises the firstregion formed under the red emission region, the second region formedunder the green emission region and the third region formed under theblue emission region; and the thickness of the first region is in therange of 1,600 to 2,200 Å, the thickness of the second region is in therange of 1,400 to 1,800 Å, and the thickness of the third region is inthe range of 1,000 to 1,400 Å.
 52. The organic light emitting device ofclaim 47, wherein the organic layer further comprises a hole transportlayer.
 53. The organic light emitting device of claim 52, wherein theemission layer comprises the red emission region, and the totalthickness of a region of the hole transport layer and the hole injectionlayer formed under the red emission region is in the range of 2,000 to2,400 Å.
 54. The organic light emitting device of claim 53, wherein thethickness of the region of the hole injection layer formed under the redemission region is in the range of 1,600 to 2,200 Å.
 55. The organiclight emitting device of claim 52, wherein the emission layer comprisesthe green emission region, and the total thickness of a region of thehole transport layer and the hole injection layer formed under the greenemission region is in the range of 1,600 to 2,000 Å.
 56. The organiclight emitting device of claim 55, wherein the thickness of the regionof the hole injection layer formed under the green emission region is inthe range of 1,400 to 1,800 Å.
 57. The organic light emitting device ofclaim 52, wherein the emission layer comprises the blue emission region,and the total thickness of a region of the hole transport layer and thehole injection layer formed under the blue emission region is in therange of 1,200 to 1,600 Å.
 58. The organic light emitting device ofclaim 57, wherein the thickness of the region of the hole injectionlayer formed under the blue emission region is in the range of 1,000 to1,400 Å.
 59. A flat panel display device comprising the organic lightemitting device of claim
 42. 60. The flat panel display of claim 59,wherein the first electrode of the organic light emitting device iselectrically connected to a source electrode or a drain electrode of athin film transistor.
 61. The organic light emitting device of claim 42,the first electrode being disposed on the substrate and being areflective electrode, the second electrode being a semitransparent ortransparent electrode, and light generated in the organic layer passingthrough the second electrode.